An Application Programming Interface (API) - in short, it’s a set of rules that lets programs talk to each other, exposing data and functionality across the internet in a consistent format.REST stands for Representational State Transfer. This is an architectural pattern that describes how distributed systems can expose a consistent interface. When people use the term ‘REST API,’ generally refers to an API accessed via HTTP protocol at a predefined set of URLs.These URLs represent various resources - any information or content accessed at that location, which can be returned as JSON, HTML, audio files, or images. Often, resources have one or more methods that can be performed on them over HTTP, like GET, POST, PATCH, PUT and DELETE. Ampcontrol, for example, provides a REST API for load management, electric fleet charging, and public charging networks. With this API, you can connect Ampcontrol to any existing software system.